Owners of conventional recreation vehicles ("RV's), also known as "caravans", which have toilets are typically faced with the unpleasant task of emptying sewage holding tanks often times on a daily basis. This chore can spoil or tarnish an otherwise wonderful camping experience. While the use of vacuum toilets can reduce the frequency of holding tank emptying since such toilets use little water, the basic problem still exists.
Some campgrounds utilize a mobile vacuum truck which travels from RV to RV, hooking up to the holding tank on the RV and sucking the contents into a storage tank on the truck. However this still requires the use of the holding tank while at the campground, which requires the users to add deodorant. Not only is the deodorant difficult to handle, and potentially toxic or irritating if it gets on the user's skin, the deodorant may interfere with on-site or municipal sewage treatment systems. Also the use of a vacuum truck requires significant labor costs for the campground.
Some campgrounds have individual campsite connections to a gravity drain system (rather than having a central dumping facility). However this also still requires the use of deodorant, and its associated disadvantages, and requires the use of large bore pipe and does not allow a construction that can follow the contour of the land. The hookup provided with the hose for a gravity feed system can be extremely messy unless a great deal of care is taken to make sure that the hose has a constant slope from the holding tank to the hookup for the gravity feed underground sewage system. If there are any low spots, sewage will collect in it, and dump out onto the ground, or at least present a significant odor problem, when the hose is disconnected or connected again.
It also has been known for some commercial housing installations to use a large central vacuum tank, which is designed to handle a certain number of toilets, and a formula is applied to size the tank based upon the number of toilets that are likely to be flushing at any one time. However such a system is impractical for the vast majority of campgrounds because it requires a large capital investment for the large pressure tank and associated pump, and because it does not allow individual units to be added without taking the risk that the system will be overloaded by too many toilets flushing at the same time.
According to the invention it is possible to eliminate the holding tank emptying problem at campgrounds. By providing vacuum installations at a campground it is possible to allow the user of an RV to make a connection between a hose and a toilet at a campground so that a holding tank is not even necessary (that is the toilet is substantially directly connected to the campground vacuum installation), or to connect from the holding tank to a vacuum source at the campground. Unlike conventional pump out stations which are common at marinas in which boats are merely connected to the station during actual sewage removal, the campground according to the invention provides constant attachment to the vacuum installation during substantially the entire time that the RV is renting space at the campground.
By the utilization of individual vacuum units/sources associated with each hookup (typically one hookup per campsite, or one hookup per two or three campsites), a number of advantages are achieved. First of all the system does not need the large capital expenditure of a single vacuum tank system, and allows the number of hook-ups to be expanded at will. Also the system according to the present invention can be above ground since the vacuum system can provide a lift of six to eight feet. Also the system is somewhat independent of gravity so that the system can be constructed to follow the contour of the land (even if underground), making it highly advantageous over convention gravity systems. Also the system can use small bore pipe (e.g. about 38 mm or about 1.5 inch, diameter) instead of large bore stand sewer pipe. Also according to one aspect of the invention existing gravity feed system campgrounds can easily be converted to vacuum systems, with the intended advantages.
According to one aspect of the invention, at a plurality of hook up points at a campground a vacuum source (above ground or underground) is provided. Extending upwardly at each hook up (e.g. campsite) at the campground is a conduit with a shut-off valve which can be connected to a hose, which in turn is connected to a part of the sewage system of an RV. Sewage from the RV sewage system is then drained directly into a (e.g. underground) sewage system at the campground. Each hook up point is isolated from the others so that flushing the toilet of one RV has no effect on the others.
According to another aspect of the invention, a campground is provided comprising: a (e.g. underground) sewage system at the campground; at least one (above ground or underground) vacuum source; and a plurality of vacuum hookups for the at least one vacuum source, each hook up constructed so that it can be connected to a sewage system on a recreation vehicle. The hookups are isolated from each other so that receipt of sewage from a recreation vehicle by one hookup does not significantly impact other recreation vehicles connected to other hookups, or to the same hookup.
The at least one vacuum source preferably comprises a stationary vacuum pump, and a vacuum tank connected to each hookup; the tanks and pump can be underground. A check valve (e.g. duckbill valve) is further preferably provided, connected between each of the vacuum tanks and the vacuum pump. Each of the hookups may comprise a conduit extending upwardly, above ground, and a shutoff valve in the conduit. The sewage system typically comprises an underground gravity sewer pipe connected to the vacuum pump. Alternatively, the vacuum source comprises an underground individual vacuum generator connected to each hookup, and the underground sewage system comprises a gravity sewer pipe connected to all of the vacuum generators. While preferably a hookup is provided for each campsite, a branched hookup can serve two or three adjacent campsites if appropriate check valves are provided in the branched connector of the hookup.
According to yet another object of the invention, a campground is provided comprising: a plurality of recreation vehicles parked at the campground, each recreation vehicle having an on-board sewage system, including a toilet (e.g. a vacuum toilet), with a discharge connection; a stationary sewage system; at least one stationary vacuum source; and a plurality of vacuum hookups for the at least one stationary vacuum source, each hook up operatively connected to the sewage system discharge on one of the parked recreation vehicles; the hookups being isolated from each other so that receipt of sewage from one of the plurality of recreation vehicles by one hookup does not significantly impact others of the plurality of recreation vehicles connected to other hookups or that hookup. The details of the campground may be as described above.
According to still another aspect of the present invention, a method of handling sewage from recreation vehicles having on board sewage systems with a toilet and a discharge connection, at a campground having at least one stationary sewage system, at least one stationary vacuum source, and a plurality of vacuum hookups for the at least one stationary vacuum source, is provided. The method comprises the steps of: (a) at the campground, parking a plurality of recreation vehicles adjacent the vacuum hookups, and operatively connecting each of a plurality of the recreation vehicle discharge connections to a plurality of the vacuum hookups; (b) maintaining the operative connections of each recreation vehicle to each vacuum hookup for a substantially continuous period of at least about eight hours typically the entire time the RV is renting the campsite!; (c) when necessary, using and flushing the toilets in each of the recreation vehicles; and (d) when a toilet is flushed in a recreation vehicle, substantially immediately drawing the sewage from flushing into the stationary sewage system using the vacuum hookup to which the recreation vehicle discharge connection is operatively connected and using the at least one stationary vacuum source, while not significantly affecting the others of the plurality of recreation vehicles.
It is the primary object of the present invention to avoid the unpleasantness associated with the emptying of RV holding tanks at campgrounds, and the practical difficulties of present campground sewage systems. This and other objects of the invention will become clear from the detailed description of the invention, and from the appended claims.